1. Field of the Invention
The invention relates to bobbin winding mechanism and more particularly to mechanism for replenishing thread on a bobbin while in place in a looptaker.
2. Description of the Prior Art
Mechanisms for replenishing thread on a bobbin while in place in a looptaker and while stitch forming instrumentalities remain operatively associated as required for sewing are well known. Such bobbin replenishing mechanisms may be seen, for example, in U.S. Pat. No. 3,115,855 of S. J. Ketterer for "Bobbin Thread Replenishment Mechanisms in Sewing Machine Loop Taker" issued Dec. 31 1963, and in U.S. Pat. No. 3,693,566, also of S. J. Ketterer for "Bobbin Thread Replenishing Mechanisms for Sewing Machines" issued Sept. 26, 1972. It has been a disadvantage of bobbin thread replenishing mechanisms of the kind disclosed in said patents that they are complex and costly due to the inclusion of camming devices for raising and lowering a drive shaft into and out of driving engagement with the bobbin. A novel arrangement for overcoming such disadvantage including a bobbin axially movable on a resilient platform into and out of a driving relationship with a bobbin winding shaft is disclosed in the U.S. Pat. No. 4,259,914 of Ralph E. Johnson for "Bobbin Winding Mechanism for a Sewing Machine", issued Apr. 7, 1981. The present invention is directed to a further improvement in bobbin winding mechanisms, and has as its prime object the provision of a bobbin winding mechanism which in addition to being simple and inexpensive to construct doesn't require axial movement of a bobbin with a platform and so results during sewing operations in a substantially noiseless operation and prevents the snagging of thread under movable parts. The arrangement of the invention is readily adaptable to use with variously constructed sewing machines incorporating different bobbin case and looptaker arrangements.